Role of angle kappa in patient dissatisfaction with refractive-design multifocal intraocular lenses

Abstract

We would like to congratulate de Vries et al.1 for their retrospective study, which looked at multiple factors in patient dissatisfaction. The authors primarily evaluated 2 diffractive intraocular lens (IOL) models and noticed that residual ametropia and astigmatism, posterior capsule opacification, and large pupil were the 3 most significant etiologies in patient dissatisfaction. In a recent prospective trial, we evaluated the visual acuity and quality-related satisfaction of patients with a refractive-design multifocal IOL and analyzed the factors that predicted dissatisfaction, including the role of angle kappa.2,A,B A total of 50 eyes of 44 consecutive patients who had phacoemulsification with multifocal IOL implantation (Rezoom, Abbott Medical Optics, Inc.) were included. At 1 year, 37 patients (43 eyes) who completed the follow-up were asked to rate their uniocular symptoms on a graded questionnaire (scale of 0 to 5 [good to bad] for 5 queries). Using regression analysis, we found that the occurrence of halos was predicted by the degree of angle kappa and diminution in uncorrected distance visual acuity (R2 = 0.26, P=.029); the occurrence of glare was predicted by the degree of angle kappa (R2 = 0.26, P=.033).2 Multiple issues are involved in the consideration of angle kappa in multifocal IOL implantation. Because of factors such as capsule contraction, memory of the haptics, and IOL rotation, it seems unlikely that a multifocal IOL intentionally decentered kappa-centrically toward the visual axis would stay in the same position during the postoperative period. Donnenfeld and HolladayC performed pupilloplasty to center the pupil and improve the waxy vision in such cases with high angle kappa. In recent years, we have been working on fibrin glue–assisted sutureless posterior chamber IOL implantation with intrascleral tuck (“glued IOL”).3 The IOL itself can be adjusted in the case of a glued IOL for aphakia by adjusting the amount of tucking, centering it according to the kappa angle.B A feasibility study of this with a glued IOL is underway in our institution, and the results may throw more light on this evolving concept. The perception of photic phenomenon is multifactorial, as evaluated in previous studies. Our study suggested there may be an additional role for misalignment between the visual and pupillary axes in the occurrence of photic phenomenon after multifocal IOL implantation. We believe the findings of de Vries et al.1and of our group2 complement each other as the studies were done of diffractive-design and refractive-design multifocal IOLs, respectively.